This invention relates to printers and, more particularly, to drive mechanisms for rolls of ribbons used in such printers
The use of electronically controlled printers of several kinds has grown rapidly. Continued decreases in costs and increases in performance suggests that this trend will continue.
The presence of various kinds of such printers in the marketplace is in response to the different requirements necessary to satisfy different segments thereof. One of these segments is the marketplace portion for label printers. Such printers print on "peel-away" labels adhering to a coated paper ribbon substrate stored usually by being wound into a roll. The coated paper substrate with the labels is fed between a pinch roller and a printing head along with an ink ribbon so that the print head may cause, by localized heating, a transfer of ink from the ribbon to a label thereagainst.
The ink ribbon is supplied from a roll of ink ribbon having a core with that ink ribbon wound thereabout. Information concerning the ink ribbon situation is often desired to use both by the operator, and by the control arrangement as a basis to make internal adjustments of parameters in the printer to obtain the best possible printing through taking into account varying ink ribbon conditions.
One known way for conveying such information to the printer control arrangement is to provide some coding scheme on the core of the ink ribbon roll through providing some markings thereon. These markings can be detected by directing light from an optical source onto a path containing the code markings and detecting the presence or absence of reflected light to an optical detector.
However, slippage between the roll of ink ribbon and the rotation support mechanism therefor can lead to errors in the optical sensing process. Similarly, such slippage can lead to smudging and smearing in the printing of the labels. Thus, there is desired a drive arrangement for the an ink ribbon roll which will avoid slippage.